Ferritin and iron are not the same things, even though they sound relatively similar (ferrous and ferritin). Instead, ferritin is a protein which stores iron and reflects just how much iron is present and available to the body.
Iron is important in the production of oxygen-carrying red blood cells. Iron is a major component of haemoglobin, a protein found in red blood cells responsible for transporting oxygen around the body. If you do not have enough iron, your body is unable to make haemoglobin and this can affect the oxygen carrying capacity of your blood. Iron is also present in myoglobin, a binding protein for iron and oxygen found in muscles. Iron is needed for other functions in the body including processes involving enzymes, the production of DNA and energy generation. Therefore, without iron, the body is unable to function properly. If iron absorption from the diet is less than the body’s requirements then iron deficiency occurs.
What is ferritin?
Ferritin is a storage protein for iron. It has a large iron core which can store up to 4000 iron atoms. These atoms are protected by the protein coat of the ferritin protein, called apoferritin. Most ferritin is found in the liver but it can also be present in the spleen, bone marrow and the muscles. Ferritin is a good indicator of how much iron is stored within our body. For example, if a blood test reveals ferritin levels are low, this could be a sign of iron deficiency anaemia.
Approximately one-quarter of the total iron in the body is stored as ferritin. Ferritin has a vital function in the absorption, storage and release of iron.
Symptoms of low ferritin
Low levels of ferritin cause symptoms such as:
- Shortness of breath
Symptoms of high ferritin
High levels of ferritin can cause iron overload also known as haemochromotosis; an inherited condition responsible for:
- Unexplained weight loss
- Abdominal pains
- Pains in the joints
- Reduced sex drive
- Muscle weakness
What are normal ferritin levels?
Ferritin is found in low concentrations in the blood and is directly proportional to the iron stores within the body. As a result, ferritin levels are used to diagnose conditions associated with low ferritin/iron levels such as iron deficiency anaemia as well as conditions associated with iron overload, including haemochromatosis and thalassemia.
Reference Ranges for Ferritin / Amount (µg/L)
Borderline low: 12-13
Normal: 13 - 150
Borderline high: 150-154
(Source: Forth Life laboratory reference range. Note reference ranges do change depending on laboratory conducting the analysis)
It is important to note that ferritin levels can be raised in certain conditions, including:
- Liver disease
- Iron supplement therapy
- Significant tissue destruction
In these instances, the increased ferritin levels are not a reflection of the body’s iron stores.
How much ferritin should I have in my blood?
Normal ferritin levels are between 13 and 150 µg/L, although this can change depending to the laboratory testing the sample. The average result of customers who have used Forth Life to test their ferritin levels is 72.93ug/L with 36% of people falling into the lower quarter of the normal range or below.
A ferritin test carried out by your doctor involves a blood sample being taken from your arm. Private online testing companies such as Forth Life offer home finger prick collection kits which allows people to collect the sample from the convenience of their home without having to visit a GP. The ferritin test shows how much iron your body has stored for future use. It is regarded as the most beneficial test for iron deficiency because ferritin levels may drop before blood iron levels do, so in effect can detect deficiency earlier. The test will highlight if you are at risk of iron deficiency or anaemia.
It is also possible for excess iron to occur, too. The ferritin test is used in combination with other tests to test for iron overload. High levels of ferritin are considered when blood levels are greater than 154 µg/L. One condition which can result from the build-up of iron is haemochromatosis which is an inherited condition and occurs over many years. The iron builds up slowly in the body and causes unpleasant symptoms. If left untreated, the condition can damage the joints as well as organs such as the heart, liver and pancreas.
Does low ferritin make you anaemic?
Because ferritin is a storage protein for iron, low ferritin levels are not the cause of anaemia, instead, low iron levels are the cause of iron deficiency or iron deficiency anaemia. However, because blood levels of ferritin are directly proportional to the body’s iron stores, ferritin is a good indicator of the condition. So, if iron levels are increased then ferritin levels will be too.
Iron deficiency usually occurs because of increased requirements or pressure on the body. For example:
- High-performance sport
- Vegetarian/vegan diet with limited iron supply
- Increased blood loss e.g. menstruation
Up to 20% of menstruating women are iron deficient and up to 5% have iron deficiency anaemia. In females, iron status is largely dependent on menstrual blood loss. In Europe, the amount of blood loss resulting from menstruation is on average 30 ml per day which is equivalent to a 0.45mg daily loss of iron. Because iron deficiency is a nutritional deficiency and is one of the most prevalent in Europe, it is possible to prevent it.
Improving iron nutrition
There are three factors to take into consideration when looking to improve your iron nutrition:
- The quantity of iron
- The quality of iron
- Composition of your diet
There are two types of iron; haem and non-haem. Haem iron is found in animal products like meat, fish and poultry. Non-haem iron is found in foods such as green leafy vegetables, cereals and legumes. In a diet which includes meat, at least 40% of the total iron absorbed by the body comes from haem iron sources, due to it being absorbed better by the body than non-haem iron. Red meats contain more haem iron than white meats such as chicken and pork and this should be taken into consideration when trying to improve your iron status. Individuals who only eat non-haem sources of iron should make sure they are getting an adequate intake. There are certain dietary components which can enhance iron absorption, too, such as vitamin C.
Because dietary iron can be poorly absorbed the body has a clever way of conserving its iron stores. When our red blood cells are broken down, the body reabsorbs the iron released from them to boost iron stores. The usual 1-2 milligram daily loss of iron is usually replenished by the absorption from dietary sources in the small intestine.
- Ferritin is not the same thing as iron, it’s a storage protein
- A ferritin protein can carry 4000 iron atoms
- The amount of ferritin present in the blood reflects the total amount of iron available to the body for future use
- Ferritin releases iron as it is required by the body for many functions including the production of new red blood cells
- Symptoms of low ferritin include fatigue, weakness, dizziness, shortness of breath and headaches
- Symptoms of high levels of ferritin include fatigue, abdominal pain, unexplained weight loss, joint pain and weakness
- You can check and monitor your own levels with one of our ferritin checks, an at home blood test kit
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Hercberg, S, Preziosi, P and Galan, P. (2001). Iron Deficiency in Europe. Public Health Nutrition: 4(2B), pp 537-545.
Hurrell, R and Egli, I. (2010). Iron Bioavailability and Dietary Reference Values. Am J Clin Nutr: 91(suppl), pp 1461S-7S.
Lopez, A et al. (2015). Iron Deficiency Anaemia. The Lancet.
Soppi, E, T. (2018). Iron Deficiency Without Anaemia – A Clinical Challenge. Clinical Case Reports.